const fp = require('lodash/fp');

const cars = [
  { name: "Ferrari FF", horsepower: 660, dollar_value: 700000, in_stock: true },
  { name: "Spyker C12 Zagato", horsepower: 650, dollar_value: 648000, in_stock: false },
  { name: "Jaguar XKR-S", horsepower: 550, dollar_value: 132000, in_stock: false },
  { name: "Audi R8", horsepower: 525, dollar_value: 114200, in_stock: false },
  { name: "Aston Martin One-77", horsepower: 750, dollar_value: 1850000, in_stock: true },
  { name: "Pagani Huayra", horsepower: 700, dollar_value: 1300000, in_stock: false },
]

// 练习 1
const isLastInStock = fp.flowRight(fp.prop('in_stock'), fp.last);
// console.log(isLastInStock(cars));

// 练习 2
const firstCarName = fp.flowRight(fp.prop('name'), fp.first);
// console.log(firstCarName(cars));

// 练习 3
const _average = function(xs) {
  return fp.reduce(fp.add, 0, xs) / xs.length;
};
const avergeDollarValue = fp.flowRight(_average, fp.map(fp.prop('dollar_value')))
// console.log(avergeDollarValue(cars))

// 练习 4
const _undersacore = fp.replace(/\W+/g, '_');
const sanitizeNames = fp.flowRight(fp.map(fp.flowRight(_undersacore, fp.toLower)));
// console.log(sanitizeNames(["Hello World", "Test test"]));
